Effects of epidermal growth factor receptor and insulin-like growth factor 1 receptor inhibition on proliferation and intracellular signaling in cutaneous SCCHN: potential for dual inhibition as a therapeutic modality

EGFR and HER-2 oncogenes expression in an experimental model of two-stage chemically induced carcinogenesis in mouse skin

The aim of the study was to investigate the expression of EGFR and HER-2 oncogenes using an experimental two stage chemically induced carcinogenesis protocol on the dorsal skin in FVB/N mice. Forty female FVB/N mice 4 weeks old, were grouped into one control (n = 8) and two experimental groups (Group A: n = 16, Group B: n = 16) following a randomization process. Two-stage carcinogenesis protocol, was implicated, including an initial treatment with 97.4 nmol DMBA on their shaved dorsal skin and subsequent treatments of 32.4 nmol TPA applications after 13 weeks for Group A and after 20 weeks for Group B. The control group C, received no treatment. Skin was examined weekly for tumor development. Post-experiment, animals were euthanized for tissue analysis. The histological status of the skin lesions in the experimental groups corresponded well with tumour advancement (from dysplasia to poorly-differentiated carcinoma). Tumour sections were evaluated histologically and immunohistochemically. EGFR expression was found significantly higher in precancerous and malignant tumours (p = 042 and p = 008 respectively), while tended to be higher in benign tumours (p = 079), compared to normal histology. Moreover, mean percentage of EGFR positive expression in malignant tumours was significantly higher than in benign tumours (p < 001). HER-2 expression was found significantly higher in precancerous and malignant tumours (p = 042 and p = 015 respectively), while tended to be higher in benign tumours (p = 085), compared to normal histology. Furthermore, mean percentage of HER-2 positive expression in malignant tumours was significantly higher than in benign tumours (p = 005). The study demonstrated that in FVB/N mice subjected to a two-stage chemically induced carcinogenesis protocol, there was a significant increase in the expression of EGFR and HER-2 oncogenes in precancerous and malignant skin lesions compared to normal tissue. This suggests a potentially early role of these oncogenes in the progression of skin tumours in this model.

Targeting receptor tyrosine kinase signaling: Avenues in the management of cutaneous squamous cell carcinoma

Non-melanoma skin cancer (NMSC) is the most frequently diagnosed cancer worldwide. Among the various types of NMSCs, cutaneous squamous cell carcinoma (cSCC) exhibits more aggressive phenotype and is also the second-most prevalent type. Receptor tyrosine kinases (RTK) triggers key signaling events that play critical roles in the development of various cancers including cSCC. Unsurprisingly, for this reason, this family of proteins has become the cynosure of anti-cancer drug discovery pipelines and is also being considered as attractive targets against cSCC. Though inhibition of RTKs in cSCC has yielded favourable results, there is still scope for bettering the therapeutic outcome. In this review, we discuss the relevance of RTK signaling in the progression of cutaneous squamous cell carcinoma, and observations from clinical trials that used RTK inhibitors against cSCC. Backed by results from preclinical studies, including those from our lab, we also give insights into the scope of using some natural products as effective suppressors of RTK signaling and skin carcinogenesis.

Dual Inhibition of EGFR and IGF-1R Signaling Leads to Enhanced Antitumor Efficacy against Esophageal Squamous Cancer

Both the epidermal growth factor receptor (EGFR) and insulin-like growth factor 1 receptor (IGF-1R) have been implicated in the development of cancers, and the increased expression of both receptors has been observed in esophageal cancer. However, the tyrosine kinase inhibitors of both receptors have thus far failed to provide clinical benefits for esophageal cancer patients. Studies have confirmed the complicated crosstalks that exist between the EGFR and IGF-1R pathways. The EGFR and IGF-1R signals act as mutual compensation pathways, thereby conveying resistance to EGFR or IGF-1R inhibitors when used alone. This study evaluated the antitumor efficacy of the EGFR/HER2 inhibitors, gefitinib and lapatinib, in combination with the IGF-1R inhibitor, linsitinib, on the esophageal squamous cell carcinoma (ESCC). Gefitinib or lapatinib, in combination with linsitinib, synergistically inhibited the proliferation, migration, and invasion of ESCC cells, caused significant cell cycle arrest, and induced marked cell apoptosis. Their combination demonstrated stronger inhibition on the activation of EGFR, HER2, and IGF-1R as well as the downstream signaling molecules. In vivo, the addition of linsitinib to gefitinib or lapatinib also potentiated the inhibition effects on the growth of xenografts. Our results suggest the next clinical exploration of the combination of gefitinib or lapatinib with linsitinib in the treatment of ESCC patients.

Regulation and Role of GLI1 in Cutaneous Squamous Cell Carcinoma Pathogenesis

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin tumor in humans. Although current therapies are sufficient to clear the tumor in many cases, the overall risk of cSCC metastasis is still 5%. Alternative treatment options could help to overcome this situation. Here we focused on the role of the Hedgehog (HH) signaling pathway and its interplay with epidermal growth factor receptor (EGFR) signaling in cSCC. The analyses revealed that, despite lack of Sonic HH (SHH) expression, a subset of human cSCC can express GLI1, a marker for active HH signaling, within distinct tumor areas. In contrast, all tumors strongly express EGFR and the hair follicle stem cell marker SOX9 at the highly proliferative tumor-stroma interface, whereas central tumor regions with a more differentiated stratum spinosum cell type lack both EGFR and SOX9 expression. In vitro experiments indicate that activation of EGFR signaling in the human cSCC cell lines SCL-1, MET-1, and MET-4 leads to GLI1 inhibition via the MEK/ERK axis without affecting cellular proliferation. Of note, EGFR activation also inhibits cellular migration of SCL-1 and MET-4 cells. Because proliferation and migration of the cells is also not altered by a GLI1 knockdown, GLI1 is apparently not involved in processes of aggressiveness in established cSCC tumors. In contrast, our data rather suggest a negative correlation between Gli1 expression level and cSCC formation because skin of Ptch^+/- mice with slightly elevated Gli1 expression levels is significantly less susceptible to chemically-induced cSCC formation compared to murine wildtype skin. Although not yet formally validated, these data open the possibility that GLI1 (and thus HH signaling) may antagonize cSCC initiation and is not involved in cSCC aggressiveness, at least in a subset of cSCC.

Squamous Cell Carcinoma with Regional Metastasis to Axilla or Groin Lymph Nodes: a Multicenter Outcome Analysis

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) of the trunk/extremities with nodal metastasis represents a rare but significant clinical challenge. Treatment patterns and outcomes are poorly described.

PATIENTS AND METHODS

Patients with cSCC who developed axilla/groin lymph node metastasis and underwent curative-intent surgery between 2005 and 2015 were identified at four Canadian academic centers. Demographics, tumor characteristics, treatment patterns, recurrence rates, and mortality were described. Overall survival (OS) and disease-free survival (DFS) were calculated using Kaplan-Meier analysis. Predictors of survival and any recurrence were explored using Cox regression and logistic regression models, respectively.

RESULTS

Of 43 patients, 70% were male (median age 74 years). Median follow-up was 38 months. Median time to nodal metastasis was 11.3 months. Thirty-one and 12 patients had nodal metastasis to the axilla and groin, respectively. A total of 72% and 7% received adjuvant and neoadjuvant radiation, respectively, while 5% received adjuvant chemotherapy. Following surgery, 26% patients developed nodal and/or distant disease recurrence. Crude mortality rate was 39.5%. Mean OS was 5.3 years [95% confidence interval (CI) 3.9-6.8 years], and 5-year OS was 55.1%. Mean DFS was 4.8 years (95% CI 3.3-6.2 years), and five-year DFS was 49.3%. Any recurrence was the only independent predictor of death [p = 0.036, odds ratio (OR) = 29.5], and extracapsular extension (p = 0.028, OR = 189) and age (p = 0.017, OR = 0.823) were independent predictors of recurrence.

CONCLUSIONS

This represents the largest contemporary series to date of outcomes for patients with axilla/groin nodal metastases from cSCC. Despite aggressive treatment, outcomes remain modest, indicating the need for a continued multidisciplinary approach and integration of new systemic agents.

Long-term Swallowing Function, Pulmonary Complications, and Quality of Life after Supracricoid Laryngectomy

Objectives

Long-term effects of supracricoid laryngectomies are nowadays under discussion. The purpose of this study was to detect the prevalence of chronic aspiration and incidence of pulmonary complications, to investigate possible influencing factors, and to analyze dysphagia-related quality of life in a cohort of patients who recovered swallowing function after undergoing supracricoid laryngectomies.

Study Design

Retrospective observational study.

Setting

San Raffaele Hospital, Vita-Salute University, Milan, Italy.

Methods

A cohort of 39 patients who recovered swallowing function free of disease after a minimum 3-year follow-up period was retrospectively investigated between October and December 2017—clinically with the Pearson’s Scale and M. D. Anderson Dysphagia Inventory and instrumentally with fiberoptic endoscopic evaluation of swallowing.

Results

Chronic aspiration was demonstrated in a significant portion of patients (clinically in 33.3% and instrumentally in 35.9%). Aspiration was influenced by advanced age at surgery ( P = .020). Type of surgical procedure, resection of 1 arytenoid cartilage, postoperative rehabilitation with a speech-language therapist, radiotherapy, age at consultation, and length of follow-up did not influence the prevalence of aspiration. Pulmonary complications affected 5 patients; incidence of pulmonary complications was related to aspiration and was favored by poor laryngeal sensation/cough reflex. Aspiration significantly affected quality of life.

Conclusions

Chronic aspiration is frequent and affects patients’ quality of life. However, incidence of pulmonary complications is low; therefore, oral feeding should not be contraindicated for aspirating patients. Preservation of laryngeal sensation and cough reflex is mandatory to prevent pulmonary complications.

The Safety and Efficacy of Expiratory Muscle Strength Training for Rehabilitation After Supracricoid Partial Laryngectomy: A Pilot Investigation

OBJECTIVES

Expiratory muscle strength training (EMST) is a safe, effective intervention that can be performed at home and may be beneficial for individuals with voice and swallowing disorders. To date there have been few studies of EMST in the head and neck cancer population, and there are no previous reports of its use after supracricoid partial laryngectomy (SCPL). The current prospective clinical pilot study was undertaken to determine the safety and efficacy of a 4-week treatment program.

METHODS

Six participants were recruited who had previously undergone SCPL, were medically stable, and had no contraindications for use of the device. At baseline, objective respiratory measurements were collected, dietary status was recorded, and participants were asked to complete a series of validated self-report instruments relating to voice, swallowing, breathing, and cough. Following the completion of treatment, baseline measures were repeated, and participant feedback was solicited.

RESULTS

The majority of individuals found the device easy to use (83%) and beneficial (83%). The side effects of treatment were relatively minor and included dizziness, muscle inflammation, and vocal fatigue. There were improvements in 2 measures from before to after treatment, namely, an average 21% increase in peak cough flow (from 371.67 to 451.33 L/min) and a 38% decrease on the Dyspnea Index (from 6.17 to 3.83). Other measures showed inconsistent changes.

CONCLUSIONS

EMST appeared to improve cough strength and reduce dyspnea symptoms after SCPL. Further study of the relative efficacy of EMST compared to other rehabilitation protocols after SCPL is needed.

Lymph-node-positive cutaneous nonmelanoma skin cancer: A poor-prognosis disease in need of treatment intensification

Locoregionally advanced nonmelanoma skin cancer (NMSC) has an aggressive clinical course characterized by high rates of treatment failure and poor survival compared with localized skin cancers. Our goal was to investigate multimodal therapy for lymph-node-positive NMSC. Data from patients with lymph-node-positive NMSC who underwent surgery and adjuvant therapy at a single tertiary center from 2002 to 2012 were retrospectively reviewed. Median follow-up was 1.8 years (range: 0.5 to 8.5). Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method. The chi-square test and logistic regression were used to determine the association between locoregional control (LRC) and the following variables: evidence of extracapsular extension, number of lymph nodes positive, largest involved lymph node, presence of a positive margin, and use of concurrent chemoradiation (CRT). Forty-six patients were evaluated, 13 (28%) of whom received adjuvant CRT. CRT patients were younger (p < 0.001) and had a significantly greater number of positive lymph nodes (p = 0.016) than patients who received adjuvant radiation alone. At 5 years, LRC was 76%, PFS was 65%, and OS was 49%. Univariate analysis demonstrated that CRT (p = 0.006), largest lymph node measurement (p = 0.039), and ≥3 involved lymph nodes (p = 0.001) predicted local recurrence. CRT (p = 0.035, odds ratio [OR] 0.20 [95% confidence interval 0.05 to 0.90]) and ≥3 involved lymph nodes (p = 0.017, OR 0.07 [95% confidence interval 0.01 to 0.62]) remained significant on multivariate analysis. CRT was well tolerated. No grade ≥3 toxicities were observed except for 1 asymptomatic grade-4 thrombocytopenia. Patients with lymph-node-positive NMSC do poorly. Patient selection for intensification of adjuvant therapy needs clarification.

Management of High-Risk Squamous Cell Carcinoma of the Skin

OPINION STATEMENT

Non-melanoma skin cancer (NMSC) is the most common malignancy in the USA, with cutaneous squamous cell carcinomas (cSCCs) constituting approximately 20 % of all NMSC. While cSCCs typically behave in an indolent fashion and can be cured with local destructive or surgical methods, a small subset metastasizes and induces significant morbidity and mortality. Identifying and aggressively treating these "high-risk" cSCCs (HRcSCCs) is thus paramount. Recent improvements in staging cSCCs appear to offer better risk stratification than earlier staging criteria. Radiologic imaging and sentinel lymph node biopsy may be beneficial in certain cases of HRcSCC, although more studies are needed before these techniques should be uniformly incorporated into management. Surgery with complete margin control, such as that offered by the Mohs micrographic technique, represents the first-line treatment for these tumors. Radiation therapy is likely most beneficial in the adjuvant setting. Chemotherapy is typically best reserved for patients with metastatic or locally advance disease that is not controllable with surgical and/or radiation therapies. Newer targeted treatments, such as EGFR inhibitors and immunotherapies may offer greater efficacy in these settings, although further evaluation is needed.

The IGF axis in HPV associated cancers

Human papillomaviruses (HPV) infect and replicate in stratified epithelium at cutaneous and mucosal surfaces. The proliferation and maintenance of keratinocytes, the cells which make up this epithelium, are controlled by a number of growth factor receptors such as the keratinocyte growth factor receptor (KGFR, also called fibroblast growth factor receptor 2b (FGFR2b)), the epithelial growth factor receptor (EGFR) and the insulin-like growth factor receptors 1 and 2 (IGF1R and IGF2R). In this review, we will delineate the mutation, gene transcription, translation and processing of the IGF axis within HPV associated cancers. The IGFs are key for developmental and postnatal growth of almost all tissues; we explore whether this crucial axis has been hijacked by HPV.

Insulin-like growth factor 1 receptor mediated tyrosine 845 phosphorylation of epidermal growth factor receptor in the presence of monoclonal antibody cetuximab

BACKGROUND

The epidermal growth factor receptor (EGFR) is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and several other human cancers. Monoclonal antibodies, such as cetuximab that block EGFR signaling, have emerged as valuable molecular targeting agents in clinical cancer therapy. Prolonged exposure to cetuximab can result in cells acquiring resistance by a process that remains incompletely understood.

METHODS

In this study, we analyzed the immediate early molecular response of cetuximab on physical interactions between EGFR and Insulin growth factor 1 like receptor (IGF-1R) in head and neck cancer cells that are resistant to cetuximab. Co-immunoprecipitation, small molecule inhibitors against phospho-Src and IGF-1R, quantitative western blot of EGFR and Src phosphorylation, cell proliferation assays were used to suggest the role of IGF-1R mediated phosphorylation of specific tyrosine Y845 on EGFR via increased heterodimerization of EGFR and IGF-1R in cetuximab resistant cells.

RESULTS

Heterodimerization of EGFR with IGF-1R was increased in cetuximab resistant HNSCC cell line UMSCC6. Basal levels of phosphorylated EGFR Y845 showed significant increase in the presence of cetuximab. Surprisingly, this activated Y845 level was not inhibited in the presence of Src inhibitor PP1. Instead, inhibition of IGF-1R by picropodophyllin (PPP) reduced the EGFR Y845 levels. Taken together, these results suggest that heterodimerization of EGFR with IGF-1R can lead to increased activity of EGFR and may be an important platform for cetuximab mediated signaling in head and neck tumors that have become resistant to anti-EGFR therapy.

CONCLUSIONS

EGFR-IGF-1R interaction has a functional consequence of phosphorylation of EGFR Y845 in cetuximab resistant HNSCC cells and dual targeting of EGFR and IGF-1R is a promising therapeutic strategy.

Interdependent epidermal growth factor receptor signalling and trafficking

Epidermal growth factor (EGF) receptor (EGFR) signalling regulates diverse cellular functions, promoting cell proliferation, differentiation, migration, cell growth and survival. EGFR signalling is critical during embryogenesis, in particular in epithelial development, and disruption of the EGFR gene results in epithelial immaturity and perinatal death. EGFR signalling also functions during wound healing responses through accelerating wound re-epithelialisation, inducing cell migration, proliferation and angiogenesis. Upregulation of EGFR signalling is often observed in carcinomas and has been shown to promote uncontrolled cell proliferation and metastasis. Therefore aberrant EGFR signalling is a common target for anticancer therapies. Various reports indicate that EGFR signalling primarily occurs at the plasma membrane and EGFR degradation following endocytosis greatly attenuates signalling. Other studies argue that EGFR internalisation is essential for complete activation of downstream signalling cascades and that endosomes can serve as signalling platforms. The aim of this review is to discuss current understanding of intersection between EGFR signalling and trafficking.

Profiling and metaanalysis of epidermal keratinocytes responses to epidermal growth factor

BACKGROUND

One challenge of systems biology is the integration of new data into the preexisting, and then re-interpretation of the integrated data. Here we use readily available metaanalysis computational methods to integrate new data on the transcriptomic effects of EGF in primary human epidermal keratinocytes with preexisting transcriptomics data in keratinocytes and in EGF-treated non-epidermal cell types.

RESULTS

We find that EGF promotes keratinocyte proliferation, attachment and motility and, surprisingly, induces DUSPs that attenuate the EGF signal. Our metaanalysis identified overlapping effects of EGF with those of IL-1 and IFNγ, activators of keratinocyte in inflammation and wound healing. We also identified the genes and pathways suppressed by EGF but induced by agents promoting epidermal differentiation. Metaanalysis comparison with the EGF effects in other cell types identified extensive similarities between responses in keratinocytes and in other epithelial cell types, but specific differences with the EGF effects in endothelial cells, and in transformed, oncogenic epithelial cell lines.

CONCLUSIONS

This work defines the specific transcriptional effects of EGF on human epidermal keratinocytes. Our approach can serve as a suitable paradigm for integration of new omics data into preexisting databases and re-analysis of the integrated data sets.